In many instances, it is preferred to utilize various supports upon which catalytically active metals are deposited to form catalytic compositions of matter which are useful in catalyzing various chemical reactions. Usually it is preferred to employ supports which possess a relatively high surface area whereby a greater amount of catalytically active metal may be deposited on the surface. One such support which has been employed in the past comprises a refractory inorganic oxide such as alumina, and specifically gamma-alumina, which possesses the aforesaid high surface area. Other forms of alumina which also have been employed will include eta- and theta-alumina, these inorganic oxides also possessing relatively high surface areas which may range from about 10 to about 500 m.sup.2 /g. In addition to this type of catalyst support, it is also known from U.S. Pat. No. 4,090,978 that electrocatalysts may be used in the preparation of electrodes for an electrochemical fuel cell. The support for an electrochemical catalyst employed in this patent uses a carbonaceous pyropolymer powder or particle upon which is impregnated a catalytic metal. However, as stated, the support is in particle form which is in contradistinction to the supports of the present invention which are shaped, that is, said supports possess a definite shape such as a sphere, plate, fiber, monolith, etc. The catalytic particles are blended with Teflon powder, a binding material, and thereafter a sheet containing the catalyst is formed by a calendering or rolling operation following which the alumina is then catalytically leached from the electrode sheet. However, the formation of the sheet requires a Teflon binder and is not a replication of any starting shape, but is formed by a calendering operation. The electrocatalyst powder of this patent, after being combined with a binder, is shaped into the desired form by means of a mold press or by any other technique possessing extremely different properties than those which are possessed by the integral shaped replications of the present invention. For example, the pore structure as measured by nitrogen adsorption or desorption, or by mercury intrusion would be very different, inasmuch as it would be changed by the presence of a binder material and by the loss of that pore structure which results from individual particles being physically bonded together. Other differences between the particles of the patent and the integral shaped replications of the present invention would be in chemical properties, electrical properties, terminal properties and mechanical properties. The chemical properties of the two composites would differ substantially, inasmuch as the presence of the binders would modify the chemical properties of the powder; the terminal properties would differ in that by using a binder with the powder, the use of a support would be limited to reactions occurring at temperatures well below 300.degree. C. as opposed to the integral shaped replications which would be stable at temperatures in excess of 500.degree. C. in non-oxidizing environments, or in crush strength in which the crush strength of the integral shaped replications is determined by the nature of the carbonaceous pyropolymer as opposed to the composite requiring a binder to hold its shape, the crush strength of such a material as being primarily determined by the crush strength of the binder material. While the patent demonstrates that micron size pyropolymer particles can be prepared from individual alumina particles which are made up of individual alumina crystalites which are strongly and chemically bonded together, the formation of relatively large spheres, plates, rods etc. which are made up of aggregates of such particles could be successfully leached after deposition of a carbonaceous pyropolymeric coating comprising recurring units containing at least carbon and hydrogen atoms to yield a macroscopic integral shaped replication of the original inorganic shaped structure.
In addition, U.S. Pat. No. 3,964,933 describes carbon particles which may be used for electrodes and a method for the manufacture thereof. However, the composition comprises a non-conductive oxide having a deposit of carbon, and not a carbonaceous pyropolymer, on the surface. The amount of carbon deposited on the surface of the oxide may be altered by extracting or leaching a portion of the oxide to provide a material which contains from 50% to about 90% carbon, the remainder of the material consisting of the oxide. As will hereinafter be shown in greater detail, this is in contradistinction to the composition of the present invention.